Installing Stiebel Tempra 24 Electric...Wire!

Hey, just throwing this out there because I'm about to attempt this at home up here in Northern Ontario on my rural farm. I have no Gas or Propane...just electric so here goes.

My service is 200 Amps, my transformer is located on my pole outside and I believe I'm the only one on it and our lines were all upgraded about 2 years out here in our township concession.

I have a 40 gallon tank that is about 30 years old now (Rheem Rudd) and is running like a champ still unbelievable. Regardless, I want to play with something new and I'm renovating downstairs and I like to tinker and get into trouble and I'm bored so I bought the Tempra 24 out of curiosity.

Now I have done/do most all my own electrical here on the farm and yes we do have an inspector check around often enough, in fact he was just here a couple months ago. Regardless I am locating my unit around 20 feet from the main panel that is in line of sight. Would I have to have a sub panel for my unit? Should I notify the Electrical Power Co about my intention to install this unit?

Does this wire have the proper amp capacity that I am needing and if so I then run from each breaker to the unit with this. At the heater from what I reading I don't hook up the ground? Is that correct or?